Abstract

Stuttering is a common disorder that affects the flow of speech and is characterised by uncontrollable repetitions, prolongations
or interruptions in speech. The aetiology of developmental stuttering is still not well understood, however genetic studies
over the past decade have made some important advances. Strong evidence for genetic factors in this disorder comes from twin
and adoption studies, as well as from family studies that include measures of familial aggregation, segregation and genetic
linkage analyses. However, Mendelian segregation of the disorder in families does not occur, and thus stuttering is a complex
genetic disorder which poses a challenge for linkage and other genetic analyses. Nevertheless, genetic linkage studies have
defined numerous loci‐carrying genes that can cause persistent stuttering, and several causative genes have recently been
identified. Application of massively parallel DNA (deoxyribonucleic acid) sequencing holds the promise of facilitating the
identification of genes that cause stuttering and other speech and language disorders.

Key Concepts

Stuttering is a disorder of the flow of speech, in which the affected individuals know what they wish to say but are unable
to say it owing to uncontrollable repetitions, prolongations or interruptions in their speech.

Developmental stuttering typically arises at a characteristic time during the acquisition of speech in children, and approximately
75–80% children recover, sometimes with and sometimes without the aid of speech therapy.

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